The invention relates to an apparatus for guidance of a cable, as claimed in the preamble of patent claim 1.
An apparatus of the abovementioned type is generally used for guiding an unshielded cable between a cable outlet from a drum, which is mounted in an autoclave such that it can rotate, and an inlet of a cable processing appliance, which is arranged outside the autoclave and is generally in the form of a continuously processing press in which the cable is provided with a sheath. Before this, insulation on the cable is dried in the autoclave and it is impregnated with a liquid impregnation agent, in particular insulating oil. A sheath quality which satisfies the desired requirements is achieved if the cable is drawn into the press with a predetermined speed and with a predetermined tensile force. These predetermined parameters are generally maintained by monitoring the speed of the cable between the cable outlet and the cable inlet, and by means of a control and regulation apparatus which compares the cable speed with nominal values and accelerates or brakes a cable drum drive if the values being compared with one another differ.
The invention, as it is defined in the patent claims, is based on the object of specifying a cable guidance apparatus of the type mentioned initially, which always ensures that the predetermined parameters are maintained with high reliability.
In the cable guidance apparatus according to the invention, the unsheathed cable is guided to form a falling cable section and a rising cable section. The position of the cable and/or a force acting on the cable can be monitored in each section, by a sensor system. If an excessive position or force error is found during this monitoring process, then the drum drive can be actuated appropriately to compensate for this error, and undesirably large fluctuations in the speed and the tensile force acting while the cable is being drawn into the cable processing appliance can in this way be avoided irrespective of the diameter of the cable or of the appliance""s cable outlet. The cable drum can thus be arranged with a horizontal or vertical axis, or with an axis aligned between the horizontal and vertical.
Since, two cable sections which are spatially separated and are subjected to different conditions can be monitored independently of one another, the cable guidance apparatus according to the invention is distinguished by particularly high operational reliability. A sheathing process provided in a downstream cable processing appliance can thus be carried out with high precision.
If at least one of the two sections of the cable which are spatially separated from one another has an additional force applied to it which, in a section facing away from the drum, can be a supporting force which is small in comparison with the predetermined and tensile force or, in a section facing the cable processing appliance, can be a prestressing force which is larger in comparison, then the force acting at the two locally separate points on the cable can be detected particularly easily and can be used in a particularly advantageous manner to control the drum drive.